1. Field of the Invention
The present invention relates to a system, including a method, apparatus and sealant composition, for effectuating repairs underwater to cracks in concrete.
2. Description of The Prior Art
At present, swimming pools and other manmade structures designed to hold or confine large volummes of water are very often formed of concrete. Concrete has the distinct advantage of very high strength and resistance to compressive forces, impermeability to water, and is not subject to corrosion or degradation with time. For this reason concrete swimming pools, spas, flood channels, culverts and other structures have been utilized for many years to confine large volummes of water.
One problem which has occurred and which has persisted throughout the years in the use of concrete structures for confining or retaining water is that cracks can develop in the concrete. Such cracks sometimes occur as a result of seismic activity of the earth. However, underwater cracks in swimming pools, dams, flood control channels and other structures used to confine large volummes of water can develop not only as a result of earthquakes, but due to other causes as well. For example, such cracks can result from explosions in the vicinity, substantial changes in the level of the water confined, erosion or settling of soil beneath or adjacent to the structure, and as a result of a variety of other causes.
Cracks that develop in the floors and walls of swimming pools and other underwater concrete structures, can create severe problems. For example, water leaking from a swimming pool through cracks in its concrete structure can place a serious financial burden on the owner of the pool to replace the water lost, since large volumes of water can be wasted in this way. Furthermore, the leakage of water through the floor or wall of a swimming pool can soften the soil in which the pool is embedded and cause weakness in the support of the pool. Cracks also weaken the structural integrity of the pool structure itself. Similar problems result from cracks in other types of concrete structures that confine large quantities of water.
A variety of different conventional approaches have been attempted to seal cracks in underwater concrete structures. For example, bituminous or tar-like sealants have been employed for this purpose. However, although these types of sealants are largely insoluble in water, they cannot be forced deep into underwater cracks. Also, such conventional materials do not adequately bond to the adjacent surfaces of fractures in the concrete. At the most, such conventional sealants form only a surface patch over the crack. Water can seep in around conventional sealants and escape through the cracks in the concrete.